Mechanical press, especially a cupping press

ABSTRACT

A mechanical press, especially for cupping operations in which a first outer slide is provided and within which a second inner slide is reciprocably mounted. A crankshaft is mounted in the press and has first throws thereon connected by connecting rods with the outer slide and second throws thereon connected by connecting rods with the inner slide. The throws for the outer slide are advanced circumferentially from the throws for the inner slide so that, when the crankshaft rotates, the outer slide will lead the inner slide. The outer slide carries a blanking die element for blanking out a work member while the inner slide carries a forming die element for draw forming the blanked out work member. The other elements of the dies are stationarily supported on the bed of the press. According to the present invention, the outer slide is elongated over conventional press slides and the inner slide is guided within the outer slide. Adjustments are provided for taking up any excess running clearances in the guiding arrangements for the slides and the press can thereby be maintained in efficient operation. The press construction is relatively simple and is strong and requires the minimum in maintenance.

lllte States Patent [191 Rirlgway et a1.

Sept. 2, 1975 1 MECHANICAL PRESS, ESPECIALLY A CUPPING PRESS [75] Inventors: Merrill L. Ridgway, Minster;

Kenneth E. Olding, Hamilton, both of Ohio [73} Assignee: The Minster Machine Company, Minster, Ohio [22] Filed: Oct. 23, 1973 [21] Appl. No.1 408,607

[52] US. Cl. 72/336; 72/347; 72/456; 100/214 [51] Int. Cl. B211) 28/00 [58] Field of Search 72/455, 456, 350, 351, 72/336, 417, 347, 348, 349, 352; 100/214 [56] References Cited UNITED STATES PATENTS 145,412 12/1873 Gordon 72/347 352,495 11/1886 Stetson 72/336 653,955 7/1900 Gordon .t 72/347 667,675 2/1901 Campbell 72/348 864,417 8/1907 Freier 72/336 1,322,533 11/1919 Candee 72/336 1,548,457 8/1925 Greayer 72/350 2,491,384 12/1949 MacMillin et a1. 100/214 2,599,022 6/1952 Sedgwick 100/214 2,745,338 5/1956 Wissman.... 100/214 2,755,147 7/1956 Ernst 100/214 3,389,653 6/1968 Hany.... 100/214 3,465,669 9/1969 Doudet 100/214 Primary Examiner-C. W. Lanham Assistant Examiner-James R. Duzan Attorney, Agent, or FirmAlbert L. Jeffers; Roger M. Rickert [5 7] ABSTRACT A mechanical press, especially for cupping operations in which a first outer slide is provided and within which a second inner slide is reciprocably mounted. A crankshaft is mounted in the press and has first throws thereon connected by connecting rods with the outer slide and second throws thereon connected by connecting rods with the inner slide. The throws for the outer slide are advanced circumferentially from the throws for the inner slide so that, when the crankshaft rotates, the outer slide will lead the inner slide. The outer slide carries a blanking die element for blanking out a work member while the inner slide carries a forming die element for draw forming the blanked out work member. The other elements of the dies are stationarily supported on the bed. of the press. According to the present invention, the outer slide is elongated over conventional press slides and the inner slide is guided within the outer slide. Adjustments are provided for taking up any excess running clearances in the guiding arrangements for the slides and the press can thereby be maintained in efficient operation. The press construction is relatively simple and is strong and requires the minimum in maintenance.

9 Claims, 11 Drawing Figures PATENTEU 21975 3802,3 2?

SHIN 1. BF 3 MECHANICAL PRESS, ESPECHALLY A CUPIPING PRESS The present invention relates to mechanical presses, and is particularly concerned with a cupping press of unique and relatively simple design,

A cupping press is a press in which stock, usually coil stock is blanked out and the blanked out work member is then formed, as by drawing, with both the blanking and drawing operations being performed in a single work cycle, with the work member remaining in the same position.

Cupping presses, due to the fact that the blanking operation must be carried out prior to the drawing operation, embody devices for causing the blanking operation to be carried out in advance of the drawing operation. Ordinarily, in a cupping press, the control of the parts of the press to cause the blanking operation to preceed the drawing operation is by the way of cams and linkages and the like. Such mechanisms are not only expensive, but are subject to wear and disorder and are, furthermore, quite often inherently weak, resulting in excessive deflections under operating loads.

The present invention proposes to provide a mechanical cupping press which is more simple in design than presses according to the prior art and more rigid, and in which maintenance problems are reduced.

More particularly, the present invention proposes the construction where a mechanical cupping press in which cams, and linkages, and the like for causing the cupping operation to follow the blanking operation are eliminated.

BRIEF SUMMARY OF THE INVENTION The present invention concerns a cupping press in which a frame is provided which has a bed and a head, or crown, spaced from the bed and uprights extending between the head and bed. Rotatably mounted in the crown, or head, is a crankshaft which is selectively driven in rotation in a conventional manner. Slidably guided on the uprights for reciprocating movement between the crown and bed, is an outer slide which has an opening extending completely therethrough in the vertical direction. Slidably guided within the opening in the outer slide is an inner slide.

Connecting rods are connected to each slide and extend upwardly therefrom into the crown of the press frame for connection to the crankshaft. The crankshaft has one set of throws thereon pertaining to the outer slide and a second set of throws thereon pertaining to the inner slide.

According to the present invention, the throws for the outer slide are circumferentially advanced relative to the throws for the inner slide so that the outer slide leads the inner slide as the crankshaft rotates. The outer slide is adapted for carrying a die element to perform blanking operations on stock fed into the press, while the inner slide is adapted for supporting a die element to carry out a cupping or drawing operation on the blanked out work member. There may also be a blankholder actuated by the outer slide. By so arranging the throws for the respective slides on the crankshaft that the outer slide leads the inner slide, all other mechanisms for causing the slides to move in sequence are eliminated and the press structure is, therefore, relatively simple but is extremely rigid, assuring a uniform flow of the workpiece material during the drawing p eration. An additional benefit of the high structural rigidity is the reduction of operating noise.

The crankshaft is advantageously journalled in the press crown by bearings which are closely adjacent to the several throws on the crankshaft and this provides extremely strong support for the crankshaft thus preventing deflection thereof during operation of the press.

Advantageously, all of the adjustments for the press pertaining to the slides can be carried out from outside the outer slide. Thus, the gibbing for the inner slide can be adjusted from outside the outer slide while adjustment of the daylight opening pertaining to each slide can also be adjusted from the outside of the outer slide. The outer slide, as mentioned, is slidably guided on the press uprights by an adjustable gib arrangement, and the outer slide is substantially longer than conventional press slides because the accuracy of the guiding of the inner slide is dependent upon :not only the gibbing between the inner slide and outer slide but upon the gibbing between the outer slide and the press uprights.

Journals of the press and the gibbing arrangement and the like in the press are advantageously lubricated by lubricant under pressure and this minimizes wear and, furthermore, increases the stiffness of the support provided by the journals and the gib arrangements.

The exact nature of the present invention and the advantages thereof will be better appreciated upon reference to the following detailed specification taken in connection with the accompanying drawings, in which:

FIG. I is a somewhat schematic side view of a press constructed according to the present invention.

FIG. 2 is a schematic view showing the inner slide of the press within the outer slide, and showing the connecting rods extending upwardly from the slides.

FIG. 3 is a perspepctive view showing a typical crankshaft for a press according to the present invention.

FIG. 4 is a schematic sectional view taken along the axis of the crankshaft showing the manner in which it is supported in the press crown.

FIGS. 5 and 6 are fragmentary sectional views through the throws for the inner slide and outer slide, respectively, showing the relationship thereof.

FIG. '7 is a graph of the motions taken by the inner and outer slides and showing the sequencing thereof.

FIG. 8 is a view, partly in section, looking in at the front of the slides, showing in more detail the relationship between the inner and outer slides and the connec tions of the connecting rods thereto.

FIG. 9 is a view looking down on top of the slides, and partly in section, and showing more in detail the gibbing pertaining to the slides.

FIG. 10 is a somewhat schematic perspective view showing the adjustable gibbing pertaining to the inner slide.

FIG. 11 is a fragmentary view showing the provision of a catch basin for lubricating fluid disposed beneath a gib for the outer slide.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings somewhat more in detail, the press shown in FIG. 1, comprises the head, or crown, portion 10, which is supported on uprights 12 which extend downwardly therefrom to a bed member 14 and which, in turn, is supported by a base 16, and base 16 and bed member 14 may be integral.

An outer slide 18 is reciprocably mounted in the press frame and is guided on uprights 12. The outer slide is provided with counterbalancing means on each side, one of which is indicated at 20 in FIG. 1.

FIG. 1 shows the press from the side and coil stock 22 is adapted to be fed therethrough in the front to back direction by a feeding mechanism, generally indicated at 24, and which is driven in synchronism with the press crankshaft which is schematically indicated at 26 in FIG. 2. The crankshaft 26 is adapted for being driven by gearing which, in turn, is adapted for being driven by a flywheel 28 which is, in turn, adapted for being driven by an electric motor 30.

V-belts, or the like, drivingly connect motor 30 with flywheel 28 and the drive leading from flywheel 28 to crankshaft 26 embodies a clutch-brake combination which is operable, when the brake is actuated, to disconnect the drive from the flywheel and to brake the drive connection against the press frame. When the brake is released and the clutch is actuated, the driving connection is released from the press frame and is clutched to flywheel 28 and causes crankshaft 26 to rotate. The particular drive arrangement extending from electric motor 30 through flywheel 28 and the aforementioned drive connection to crankshaft 26 is substantially conventional and is not described in detail in the present application.

FIG. 2, which is a schematic front view of the press, will show that there is an inner slide 32 disposed inside outer slide 18. Outer slide 18 has connecting rods 34 pertaining thereto extending upwardly into crown of the press, while inner slide 32 has connecting rods 36 connected thereto and extending upwardly into the crown of the press. The connecting rods are adapted for engagement with respective throws provided on crankshaft 26.

As will be seen in FIG. 3, crankshaft 26 has an outermost pair of throws 38 which pertain to outer slide 18 and to which the upper ends of connecting rods 34 are connected in a conventional manner. Crankshaft 26 also comprises an inner pair of throws 40 pertaining to the inner slide 32 and to which the upper ends of con .necting rods 36 are connected.

According to the present invention, and as will be seen in FIG. 3, throws 38 are displaced angularly from throws 40 and, specifically, in the direction of rotation of crankshaft 26. In the particular crankshaft illustrated, throws 38 lead throws 40 by IOO, but the particular angle between throws 38 and throws 40 is variable in conformity with the particular die arrangement which is to be placed in the press. The crankshaft is a single forged member with the throws integral therewith and is, thus, extremely strong and rigid. The press may be so constructed that the crankshaft is driven from either one or both ends, but is preferably driven from both ends in order to minimize twisting thereof. Such twisting of the crankshaft could cause sufficient angular motion relatively of the throws of a respective pair thereof to cause the pertaining slide to tilt in the press. By driving the crankshaft at each end, such twist ing is eliminated. The crankshaft could, of course, be driven from one end only if made sufficiently massive for the work operation to be performed.

FIG. 4 schematically illustrates the manner in which crankshaft 26 is supported in crown 10 of the press. In FIG. 4, it will be seen that the crankshaft is provided with shell type bearing sleeves, generally indicated at 42, and which are clamped in place about the crankshaft as by bearing caps 44. The bearing shells, or sleeves, immediately outside the outer throws 38 are flanged on the throw side and thus serve as thrust bearings for the crankshaft assembly. It will be noted that the bearings are disposed closely adjacent the throws on opposite sides thereof and thereby firmly support the crankshaft against bending due to the loads imposed thereon by the respective slides.

The bearings are preferably pressure lubricated and this is accomplished by conduit means 46 leading through bearing caps 44 and connected to a source of lubricant under pressure. The lubricant supply to individual bearings can be controlled in any suitable manner, such as by needle valves. The throws of the crankshaft can also be pressure lubricated by lubricant conducted thereto via passages formed in the connections 34 and 36.

FIGS. 5 and 6 demonstrate the relative sizes and the angular orientation of the throws 38 and 40. FIG. 5 shows a throw 38 and FIG. 6 shows a throw 40. Assuming the direction of rotation of the crankshaft, as is viewed in FIGS. 5 and 6, to be counterclockwise it will be seen that throws 38 lead throws 40 by about Further, the throws 38 provide for a substantially smaller amount of movement of the outer slide than is provided for the inner slide by throws 40. This comes about because outer slide 18 carries out the blanking operation which requires only a relatively small storke, while inner slide 32 carries out the drawing operation, which requires a substantially longer stroke.

More specifically, and with reference to FIG. 7, in the particular press illustrated, outer slide 18 has a total stroke of about two inches, whereas inner slide 32 has a total stroke of about 6 and /2 inches. FIG. 7 also indicates the amount of lead of the outer slide over the inner slide. This lead will be seen to be 100 for the particular press illustrated in this application. As mentioned however, different lead angles, as well as different slide strokes, can be provided in conformity with the particular work operation that is being carried out.

In most cupping operations, the blanked out work member is held by a blank holder, while the drawing operation is carried out. In FIG. 7, the point marked A is that point at which the blank holder which is actuated by outer slide, leaves the blank. Further points indicated on FIG. 7 are point B at which the draw punch protrudes beyond the blanker punch the greatest distance and also the point at which the inner and outer slide faces are the nearest together measured in the vertical direction and point C at which the blanker punch protrudes beyond the draw punch the greatest distance and also the point at which the slide faces are the farthest apart measured in the vertical direction. The peaks of the two curves represent the upper and lower limits of movement of the respective slides. The curve pertaining to slide 18 has the reference numeral 18 applied thereto, whereas the curve pertaining to inner slide 32 has the reference numeral 32 applied thereto.

FIG. 8 is a rather detailed showing of the relation between the slides and shows slides 18 and 32 and the connecting rods 34 and 36, respectively, connected thereto. As will be seen in FIG. 8, the lower end of each of the connecting rods 34 is connected by a pin 50 to the head of a screw 52 that threadedly engages a nut 54 having a worm wheel 56 keyed thereto that is engaged by rotatable worm 58. Both of the connecting rods 34 are similarly constructed and the worms 58 pertaining thereto are geared together to turn in unison so that the effective length of both of the connecting rods 34 can be adjusted at the same time by adjustment of only one of the worms.

The nut 54 and worm wheel 56 are held in position in a recess in slide 18 by a flanged clamp member 60.

The same sort of arrangement is provided in respect of the nuts which connect rods 36 for inner slide 32; with the screw pertaining thereto being indicated at 63, the nut at 65, the worm wheel at 67 and the worm at 69. The worms 69 for the connecting rods 36 are also geared together so that the adjustment of the only thereof is operable for adjusting the effective lengths of both of the connecting rods 36 at one time.

FIG. 8 also shows the provision of a catch basin 71 beneath the gibbingfor the inner slide. This catch basin 71 catches lubricant flowing out from between the gibs and conveys it to a trough 73 from which the lubricating fluid is recovered and recirculated. As will be seen hereinafter, the gibbing for the outer slide is also provided with catch basins so that lubricant can be received therefrom and recirculated.

FIG. 9 shows more in detail the gibbing for the outer slide 18 and the inner slide 32. Referring first to the gibbing for the outer slide, the uprights 12 of which there is one on each side, each carry at the front and back of the press an angular member 60 adjustable in the fore and aft direction of the press into slidable engagement with a gib element 62 carried by slide 18. Slide 18 carries a further gib element 64 engaging member 60 at right angles to the direction of engagement of gib 62 and gib 64 is backed up by a tapered strip.66 which is also adjustable in the fore and aft direction of the press slide thereby to adjust gib member 64 in the lateral direction. With a gibbing arrangement, as described, in each corner, the outer slide has eight point support and is, thus, accurately guided on the press uprights 12 during reciprocating movement therein. 1

In respect of the gibbing between inner slide 32 and outer slide 18, at the rear of the inner slide there are flat gib members 68 on the inner slide which are engaged by wear plates 70 which are mounted on support members 72 carried inside the outer slide. Support plates 72 and wear plates 70 are fixed in place on the outer slide as by cap screws 74.

At each front corner of the inner slide, the slide has mounted thereon a gib member 76 extending at 45 to the center line of the inner slide so that the members 76 on opposite sides of the inner slide converge toward the front of the press. Each member 76 is engaged by an adjustable member 78 which has a 45 inclined on one side engaging the respective member 76 and an incline 80 of a smaller angularity on the opposite side.

The inclined surface 80 of member 78 is engaged by a correspondingly inclined surface on a wedge member 82. The members 78 and 82 are supported in an angular support plate 84 connected to the inside of the outer slide as by cap screws 86. Cap crews 88 extend through the front of the outer slide and through member 84 and threadedly engage wedge member 82 for adjustment of the wedge member in-the fore and aft direction of the press. Similarly, cap screws 90 extend through the front of the outer slide and through member 84 and threadedly engage member 78. The apertures in the outer slide 18 and the support member 84 for screws 90 are clearance holes so that member 78 can be adjusted laterally in order to locate inner slide 32 quite accurately within the outer slide.

The gibbing for the inner slide 32 that is mounted on the inside of the outer slide 18 is of sufficient length that the inner slide is always contained within the gibbing and is, thus, quite accurately guided at all times. It will also be appreciated that all adjustments of the gibbing for the inner slide 32 can be made from outside the outer slide. The various screws and the like are distributed vertically along the outer slide so that selective adjustment of different regions of the gibbing can be made.

FIG. 9 also shows a door 92 provided on the outer slide which covers an opening 94 therein through which access can be had to the adjacent worm 69 for adjustment of the shut height pertaining to the inner slide 32. Slide 18-also may have openings 93 therein (FIG. 2) through which access may be gained to the inner slide for attachment of the draw punches.

FIGS. 8 and 9 also will show that the inner slide 32 is provided with a single counterbalancing cylinder arrangement 96 which, similarly to the countcrbalancing arrangement 20 for the outer slide is advantageously pneumatically operated.

FIG. 10 is a perspective view. schematically illustrating the gibbing pertaining to the inner slide 32 and mounted within the outer slide. The various parts of the gibbing arrangement of FIG. 10 carry the same num bers as in FIGS. 8 and 9, while the distribution of the clamp screws, etc., along the length of the various members is indicated. This view will also show the surface of member 78 which engages the gib 76 is pro vided with a zig-Zag groove 98 formed therein and terminating at both ends within the limits of the inclined surface which engages member 76. Lubricating fluid under pressure can be supplied to groove 98 via passage 100 and the lubricant which flows out from be tween the opposed relatively slidable members of the gib arrangement will flow downwardly therealong and be captured by catch basin 71. A similar catch basin is provided for each of the gibs at each corner of the inner slide and all of the gib surfaces provided with lubricating fluid under pressure.

The relatively moveable gib surfaces pertaining to the outer slide are also provided with a catch basin as schematically illustrated in FIG. 11. In FIG. 11, the lower end of the gibbing for one of the corners of the outer slide is schematically indicated at 102, and therebeneath is a catch basin 104 into which fluid flowing from the givs will be received. The press is provided with other troughs, catch basins and the like for collecting circulating fluid so that it can be returned to aa reservoir and be recirculated through the press structure.

From the foregoing, it will be evident that the press according to the present invention is relatively simple in construction but provides for extremely accurate and firm guiding of the inner slide and provides for sequential operation of the outer and inner slides without the provision of expensive and troublesome cams and linkages and levers and the like.

Modifications may be made within the scope of the appended claims.

We claim:

1. In a mechanical press; a press frame having a crown and a bed and uprights extending between the crown and head, an outer slide, first means including cooperating elements of gib means on said uprights and the corners of side outer slide for guiding said outer slide on said uprights for movement toward and away from the bed, said elements of gib means having two interengaged angularly related surfaces perpendicular to each other on a single member at each corner of the outer slide and said elements of gib means being relatively adjustable, an inner slide, second means guiding said inner slide in said outer slide for movement parallel to the movement of the outer slide, a crankshaft rotatable in the crown, a respective pair of throws on the crankshaft for each slide, and a respective pair of connecting rods for each slide, each connecting rod having one end pivotally connected to the respective slide and the other end engaging a pertaining throw of the crankshaft, means for adjusting the effective location of the die mounting surface of the slide with respect to the location of the lower end of the connecting rods, the said throws pertaining to one of said slides being angularly offset from the throws pertaining to the other whereby upon rotation of said crankshaft one of said slides will lead the other thereof in both directions of movement of the slides.

2. A mechanical press according to claim 1 in which the throws pertaining to the outer slide are offset forwardly from the throws pertaining to the inner slide whereby the outer slide leads the inner slide.

3. A mechanical press according to claim 1 in which said second means comprises cooperating elements of gib means on the corners of said inner slide and in said outer slide, said elements of gib means having interengaged surfaces, said elements of gib means on one side of the inner slide having the interengaged surfaces thereof parallel to a first plane and said elements of gib means on the opposite side of the inner slide having the interengaged surfaces thereof in respective second planes which are disposed at an angle to said first plane and to each other.

4. A mechanical press according to claim 3 in which each said second plane makes an angle of about 45 with the first plane, said second planes being substantially perpendicular to each other and converging in a direction away from the respective side of the inner slide.

5. A mechanical press according to claim 3 in which said elements of gib means for said inner slide includes elements adjustably mounted in said outer slide, and means adjustably securing the elements in said outer slide and accessible from the outside of said outer slide.

6. In a mechanical press; a press frame having a crown and a bed and uprights extending between the crown and bed, an outer slide, first means guiding said outer slide on said uprights for movement toward and away from the bed, an inner slide, second means guiding said inner slide in said outer slide for movement parallel to the movement of the outer slide, a crankshaft rotatable in the crown, a respective pair of throws on the crankshaft for each slide, and a respective pair of connecting rods for each slide, each connecting rod having one end pivotally connected to the respective slide and the other end engaging a pertaining throw of the crankshaft, means for adjusting the effective location of the die mounting surface of the slide with respect to the location of the lower end of the connecting rods, the said throws pertaining to one of said slides being angularly offset from the throws pertaining to the other whereby upon rotation of said crankshaft one of said slides will lead the other thereof in both directions of movement of the slides, said outer slide has parallel front and back portions and parallel side portions perpendicular to said front and back portions, said portions defining a rectangular opening extending through said outer slide to receive said inner slide, said first means comprising cooperating elements of first giv means on said uprights and on the corners of said outer slide having angularly related interengaged first guide surfaces, said second means comprising cooperating elements of second gib means in opening in said outer slide and on the corners of said inner slide having interengaged second guide surfaces parallel to said first guide surfaces, the height of said outer slide in a direction of the axis of the said opening therein being substantially greater than the height of said inner slide measured in the same direction.

7. A mechanical press according to claim 6 in which said first guide surfaces comprise a pair of angularly related surfaces at each corner of the outer slide and said first gib means being adjustable for selectively adjusting said angularly related surfaces relatively.

8. A mechanical press according to claim 6 which includes means for supplying fluid under pressure to the said interengaged guide surfaces, and catch trough means beneath said gib means for receiving fluid which drains from said guide surfaces.

9. A mechanical press according to claim 8 in which said guide surfaces are vertical and said catch trough means includes a trough in said outer slide under each second gib means and a trough in said frame under each first gib means, said troughs adapted to drain to a collection region from which the fiuid can be returned to said guide surfaces.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,902,347 DATED September 2, 1975 INVENTOR(S) Merrill L. Ridgway and Kenneth E. Olding It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 2, line 37, "perspepctive" should be perspective Col. 4, line 29, "storke" should be stroke Col. 5, line 13, "the" second occurrence, should be one Col. 5, line 54, "inclined" should be incline Col. 6, line 51, "givs" should be gibs Col. 6, line 53, "aa" should be a Col. 8, line 23 (Claim 6), "giv" should be gib Signed and Scaled this sixth D y of January 1976 [SEAL] A ttes t:

RUTH C. MASON C. MARSHALL DANN Arresting ()jfit r Commissioner oj'latems and Trademarks 

1. In a mechanical press; a press frame having a crown and a bed and uprights extending between the crown and head, an outer slide, first means including cooperating elements of gib means on said uprights and the corners of side outer slide for guiding said outer slide on said uprights for movement toward and away from the bed, said elements of gib means having two interengaged angularly related surfaces perpendicular to each other on a single member at each corner of the outer slide and said elements of gib means being relatively adjustable, an inner slide, second means guiding said inner slide in said outer slide for movement parallel to the movement of the outer slide, a crankshaft rotatable in the crown, a respective pair of throws on the crankshaft for each slide, and a respective pair of connecting rods for each slide, each connecting rod having one end pivotally connected to the respective slide and the other end engaging a pertaining throw of the crankshaft, means for adjusting the effective location of the die mounting surface of the slide with respect to the location of the lower end of the connecting rods, the said throws pertaining to one of said slides being angularly offset from the throws pertaining to the other whereby upon rotation of said crankshaft one of said slides will lead the other thereof in both directions of movement of the slides.
 2. A mechanical press according to claim 1 in which the throws pertaining to the outer slide are offset forwardly from the throws pertaining to the inner slide whereby the outer slide leads the inner slide.
 3. A mechanical press according to claim 1 in which said second means comprises cooperating elements of gib means on the corners of said inner slide and in said outer slide, said elements of gib means having interengaged surfaces, said elements of gib means on one side of the inner slide having the interengaged surfaces thereof parallel to a first plane and said elements of gib means on the opposite side of the inner slide having the interengaged surfaces thereof in respective second planes which are disposed at an angle to said first plane and to each other.
 4. A mechanical press according to claim 3 in which each said second plane makes an angle of about 45* with the first plane, said second planes being substantially perpendicular to each other and converging in a direction away from the respective side of the inner slide.
 5. A mechanical press according to claim 3 in which said elements of gib means for said inner slide includes elements adjustably mounted in said outer slide, and means adjustably securing the elements in said outer slide and accessible from the outside of said outer slide.
 6. In a mechanical press; a press frame having a crown and a bed and uprights extending between the crown and bed, an outer slide, first means guiding said outer slide on said uprights for movement toward and away from the bed, an inner slide, second means guiding said inner slide in said outer slide for movement parallel to the movement of the outer slide, a crankshaft rotatable in the crown, a respective pair of throws on the crankshaft for each slide, and a respective pair of connecting rods for each slide, each connecting rod having one end pivotally connected to the respective slide and the other end engaging a pertaining throw of the crankshaft, means for adjusting the effective location of the die mounting surface of the slide with respect to the location of the lower end of the connecting rods, the said throws pertaining to one of said slides being angularly offset from the throws pertaining to the other whereby upon rotation of said crankshaft one of said slides will lead the other thereof in both directions of movement of the slides, said outer slide has parallel front and back portions and parallel side portions perpendicular to said front and back portions, said portions defining a rectangular opening extending through said outer slide to receive said inner slide, said first means comprising cooperating elements of first giv means on said uprights and on the corners of said outer slide having angularly related interengaged first guide surfaces, said second means comprising cooperating elements of second gib means in opening in said outer slide and on the corners of said inner slide having interengaged second guide surfaces parallel to said first guide surfaces, the height of said outer slide in a direction of the axis of the said opening therein being substantially greater than the height of said inner slide measured in the same direction.
 7. A mechanical press according to claim 6 in which said first guide surfaces comprise a pair of angularly related surfaces at each corner of the outer slide and said first gib means being adjustable for selectively adjusting said angularly related surfaces relatively.
 8. A mechanical press according to claim 6 which includes means for supplying fluid under pressure to the said interengaged guide surfaces, and catch trough means beneath said gib means for receiving fluid which drains from said guide surfaces.
 9. A mechanical press according to claim 8 in which said guide surfaces are vertical and said catch trough means includes a trough in said outer slide under each second gib means and a trough in said frame under each first gib means, said troughs adapted to drain to a collection regIon from which the fluid can be returned to said guide surfaces. 